Canine biscuit containing discrete particles of meat and other materials and method for making same

ABSTRACT

A dry hard canine biscuit having visually apparent, discrete particles, which contain (i) meat and/or meat by-product and/or (ii) farinaceous material and/or textured vegetable protein, distributed substantially uniformly throughout the biscuit is obtained by blending the non-fat solids portion of a canine biscuit dough with the particles which are substantially inert with respect to the dog biscuit dough, mixing the dry-blended mixture with water and with the fat portion of the pet biscuit dough to form a dough, forming the dough using low shear into pieces, and baking and drying the formed pieces to obtain a microbiologically stable product which can be packaged without a barrier material. The particle inertness is made possible by using particles having: (1) a moisture content of 35 percent by weight or less and (2) a water activity which is less than the water activity of said biscuit dough. There is a substantial absence of particle color bleed into the biscuit. An example of the textured vegetable protein is textured soy protein; and an example of the farinaceous material is wheat. The discrete, visually apparent dehydrated particles enhance the palatability and visual attractiveness of the dry biscuit.

This is a continuation-in-part of U.S. Ser. No. 341,969, filed on Jan.22, 1982.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for incorporating animal protein intoa biscuit dough to obtain a dry hard canine biscuit having animalprotein particles which are visually apparent as discrete particles andwhich are distributed substantially uniformly throughout the biscuit.The invention also relates to a dry hard canine biscuit containingdiscrete animal protein particles. The invention products have enhancedpalatability and enhanced eye appeal. The invention further relates to amethod of preparing such particles.

2. Description of the Prior Art

Dry pet foods are commonly cereal type materials having a low moisturecontent of less than about 15 percent by weight. As a result of theirlow moisture content, they resist mold growth and bacterial spoilage.Additionally, they can often be packaged and stored in containers, suchas a box, without the need for hermetic sealing and without the need fora moisture barrier. Dry pet foods typically have low palatabilitybecause of their low moisture content.

The incorporation of meat products, fish products, and poulty productsinto a farinaceous pet food to improve palatability and to improvenutritional values of dry pet foods, intermediate moisture products andhigh moisture content pet foods (more than about 50 percent by weight ofwater) is known in the art.

U.S. Pat. No. 3,946,123 discloses an aqueous suspension or broth of meatand meat by-products consisting in part or entirely of fish and flavoredcereal chunks. The meat and meat by-products that may be used includethose of fowl and fish as well as that of mammals such as cattle, swine,goats and the like. Due to the high moisture content of the product, itmust be packaged in cans. In U.S. Pat. No. 4,158,706 a high moisture petfood product containing farinaceous and proteinaceous components such asmeats, fish and poultry is impregnated with a preservative such assuccinic acid to enable packaging within a paper or polymer film. Thesehigh moisture content products have a high shipping weight for a givenamount of nutritive value and do not provide a hard surface for thestrengthening of gums and for the removal of plague from teeth.

The production of dry pet foods which contain proteinaceous andfarinaceous material is disclosed in U.S. Pat. Nos. 3,962,462,4,020,187, 4,039,689, 4,055,681, 4,145,447, 4,215,149 and 4,229,485.

In U.S. Pat. No. 3,962,462 the ingredients are first dry-blended andthen water and water-containing ingredients are added until a cohesivedough is formed. A stabilizing system comprising a sugar, an edible acidand an antimycotic provides stability within the pet food when the petfood is subject to semi-moist conditions. The product is produced inwafer form for packaging with a semi-moist pet food. The proteinaceousmaterial includes meat, such as the flesh of cattle, swine, sheep,poulty and fish, as well as various meals such as meat and bone meal,fish meal and the like.

In U.S. Pat. No. 4,020,187 tallow or lard is added to a water slurry ofa ground mixture of meat and meat by-products to raise the resulting fatcontent of the mixture to at least 25 percent. The resulting mixture isthen homogenized to liquefy and reduce the particle size and touniformly distribute the fat content through the meat mixture. Dryfarinaceous ingredients are ground and added to the homogenized meatmixture. The blended mixture is subjected to temperatures of from 225°to 325° F. at a pressure of at least about 50 p.s.i. The product isexpanded, cut and dried to obtain a product having a final moisturecontent of from 7 to 15 percent. The product, it is disclosed, is notexternally greasy and may be packaged in ordinary paper bags or inplastic wrap.

A dry, but soft, pet food is produced in U.S. Pat. No. 4,039,689 usinglow temperatures and pressures. The use of the low processingtemperatures, less than about 130° F., leads to the soft dry nature ofthe pet food, it is disclosed. Meat and meat by-products as well asdried animal by-products can be used as a protein source for the petfood in U.S. Pat. No. 4,039,689. The dried animal by-products includemeat meal and bone meal.

U.S. Pat. No. 4,055,681, like U.S. Pat. No. 4,039,689, produces a softdry pet food having meat-like texture and appearance. Meat meal isdisclosed as a protein source and fresh meat and meat by-products areused to impart palatability to the pet food.

In the production of the dry pet food products according to theprocesses of the above patents, the use of wet meat products causessubstantial smearing or blending of the meat into the farinaceousmaterial. It also causes bleeding of the protein colors into thefarinaceous material which reduces the visual attractiveness of theproduct to the consumer and which reduces the product's hardness.

A hard dry pet food is produced in U.S. Pat. No. 4,145,447. Highpressures of at least about 100 p.s.i. are used to obtain a productwhich is hard enough to provide chew-resistance for the removal ofplaque or tartar from the animal's teeth. The product is a long-lastingone which requires about 30 minutes to 2 hours for a 25 lb. dog toconsume. Dry components are mixed until homogeneous and then sufficientwater is added to wet the product without affecting the apparent dry,free-flowing characteristic of the product. The wetted product is thencompacted at a pressure of at least 100 p.s.i., followed by heating orbaking the compacted product at a temperature of at least about 200° F.The product can contain air-dried, freeze-dried or irradiated foods suchas meat, fish, fish meal, cereals, fruits, vegetables and the like.Protein fibers, such as those derived from soy protein and wheat gluten,or animal fibers, such as those derived from skin, muscles, andintestines, are optionally added to support the structure of theproduct. The animal fibers can be prepared by cutting, chipping,grinding, shredding, shearing or beating animal skins such as cowhide orrawhide. The high pressures used in the process of U.S. Pat. No.4,145,447 makes the process costly. Also, the structure-supportingfibers derived from animal tissue, which are optionally used in theprocess of U.S. Pat. No. 4,145,447, are low in palatability.Furthermore, a product having discrete, visually apparent, meatparticles is not disclosed.

U.S. Pat. Nos. 4,215,149 and 4,229,485 disclose processes for improvingthe palatability of dry pet foods by applying a coating which containsproteins derived from animals, to the surface of the pet food. In U.S.Pat. No. 4,215,149 the surface of the pet food is treated with fat andthen with a phosphoric acid salt. Treatment of the surface of the petfood with meat flavors and animal proteins is optional. Heating of thecoated pet food, it is disclosed, must be avoided.

In U.S. Pat. No. 4,229,485 a dry biscuit is coated with a continuousglazed liver coating and is then baked to less than 18 percent moistureby weight. The liver preferably constitutes at least about 50 percent byweight of the coating, exclusive of moisture. The liver coating containsfarinaceous material and comminuted liver. The hard glazed coating, itis disclosed, has the visual appearance of a meat coating to enhance theproduct's attractiveness to pets. The dry biscuits to which the livercoating is applied are obtained by baking a combination of uncookedfarinaceous material and uncooked meat or meat by-products. The use ofthe uncooked meat or meat by-products in the form of finely cut flakes,preferably having their largest dimension in the range of 0.015 inch to0.250 inch, it is disclosed, is necessary for obtaining highpalatability of the product. However, the use of uncooked meat or meatby-products result in the blending of the protein color into thefarinaceous material. Additionally, the flakes present in the biscuitare not visually apparent because of the liver coating.

U.S. Pat. No. 4,310,558 teaches producing a dry pet food productcontaining fibrous food pieces having a tough, pliable texture combinedwith a basal matrix containing proteinaceous and farinaceous materialshaving a porous texture and appearance. The fibrous food pieces, whichmay simulate vegetables, grains and red meat pieces, comprise denaturedproteinaceous material. The food pieces are blended with undenaturedproteinaceous materials and farinaceous materials. The mixture ismechanically worked under conditions of elevated temperature andpressure and finally extruded to form an expanded dry pet food producthaving a porous texture interspersed with food pieces having a tough,pliable fibrous texture. The mechanical working and forming is basicallydone in a cooker extruder, which utilizes high shear and substantialpressure.

BROAD DESCRIPTION OF THE INVENTION

An object of the invention is to provide dry hard canine biscuits, whichcontain meat and/or meat by-product plus farinaceous material and/ortextured vegetable protein, distributed substantially uniformlythroughout the biscuits. Another object of the invention is to provide amethod for making such dry hard canine biscuits. A further object of theinvention is to provide dry hard canine biscuits and method of producingsuch biscuits which overcomes the disadvantages of the above prior art.A still further object of the invention is to provide a process formaking such particles. Other objects and advantages of the prior art areset out herein or obvious herefrom to one ordinarily skilled in the art.

The objects and advantages of the invention are achieved by the dry hardcanine biscuit and the production method of the invention.

According to the invention, there is provided a dry hard canine biscuithaving discrete particles, which contain meat and/or meat by-product andwhich can also contain farinaceous material and/or textured vegetableprotein, distributed substantially uniformly throughout the biscuit. Theparticles are visually apparent as discrete particles, do not separatefrom the remaining, or farinaceous portion of the biscuit duringshipping, and enhance the palatability of the biscuit by providing aflavor impact. The product is highly stable and can be packaged directlyinto a paperboard box. The method for making the dry hard canine biscuitof the invention is economical, does not involve the use of highpressures and/or high shear to compact the biscuit dough as in U.S. Pat.Nos. 4,145,447 or 4,229,485, avoids substantial bleeding of the animalprotein color into the farinaceous material, maintains particlediscreteness and achieves substantially uniform distribution of theparticles throughout the biscuit. Even with the inclusion of farinaceousmaterial and/or textured vegetable protein in the particles, there isnot any loss of discreteness of the particles in the final dry hardcanine biscuit. Suitable food-pet food grade dyes are used for theformation of the particles in order to color dark brown the farinaceousmaterial and/or textured vegetable protein in the particles. Such dyedoes not run, bleed or the like when the particles are incorporated intothe final biscuit.

The invention includes a method for making a dry hard canine biscuithaving enhanced palatability and enhanced eye appeal. Discreteparticles, which contain meat and/or meat by-product and which can alsocontain farinaceous material and/or textured vegetable protein aredistributed substantially uniformly throughout the dry biscuit and arevisually apparent to the consumer as discrete particles. The presence ofmeat-containing particles substantially above or on the biscuit surfaceis kept to a minimum to reduce the opportunity for meat particle lossfrom physical abuse during transit. This particle distribution isaccomplished by first dry-blending the meat particles with the non-fatsolids portion of a biscuit dough, admixing the dry-blended mixture withwater and then adding the fat portion of the biscuit dough to form adough. The invention process forms the dough using low pressure and/orlow shear, preferably as little pressure and/or shear as possible,forming means or techniques. Alternatively, the water and fat can beadmixed simultaneously with the dry-blended mixture. Meat and/or meatby-product containing particle visual awareness and biscuit hardnessmaintenance are achieved by using particles which are inert with respectto the biscuit dough. Meat and/or meat by-product containing particleinertness is made possible through the use of particles: (a) having amoisture content of 35 percent by weight or less; and (b) having a wateractivity which is less than the water activity of the biscuit doughduring mixing, if the biscuit dough ingredients were mixed withoutparticles containing the meat and/or meat by-product.

The invention also includes a process for preparing the particles whichcontain meat and/or meat by-product plus farinaceous material and/ortextured vegetable protein. The inclusion of the non-meat and/ornon-meat by-product material in the particles provides a significantcost reduction as compared to all meat and/or meat by-product particles.Particles of meat and/or meat by-product plus farinaceous material plustextured vegetable protein which are stable, cohesive and have particleintegrity as such or in a biscuit, is unexpected to the art.

The process for preparing the dry, cohesive particles, which containmeat and/or meat by-product plus farinaceous material and/or texturedvegetable protein, includes admixing the meat in particulate form and/ormeat by-product in particulate form with the farinaceous material inparticulate form and/or the vegetable protein in particulate form. Theadmixture is formed by mechanically working the mass at conditions ofelevated temperature above about 212° F. and pressure for a timesufficient to convert the mass into a flowable substance and extrudingthe flowable substance through a restricted orifice. The extrudate isparticulated and the particles are dried to form dry, cohesiveparticles.

DETAILED DESCRIPTION OF THE INVENTION

The dry hard canine biscuit of the invention comprises discrete,visually-apparent particles, which contain meat and/or meat by-productand which can also contain farinaceous material and/or texturedvegetable protein, which are uniformly distributed throughout thebiscuit. The remaining, or non-meat and/or non-meat by-product particleportion of the biscuit is substantially free of meat particle color. Thebiscuits are very stable microbiologically, and can be stored withoutrefrigeration and without a packaging barrier material such as plasticfilm. The biscuit can be in various shapes such as square, round,triangular, animal-shaped and the like. The preferred shapes are round,T-bone shape and a chop or steak-like shape. The biscuits can have athickness typical of canine biscuits. A preferred thickness is about 1/2inch.

The particles containing meat and/or meat by-product used in theinvention can be in the form of specs, flakes, chunks, chips, granulesand the like. Herein, unless otherwise noted, the phrase "particlescontaining meat and/or meat by-product" or its equivalent wording ismeant to include the partial substitution by the farinaceous materialand/or textured vegetable protein for the meat and/or meat by-product inthe particles. The particles should be of sufficient size so as to bevisually apparent to the consumer as discrete particles when in thebiscuit of the invention. Prior to incorporation into the biscuit, theparticles containing meat and/or meat by-product should preferably havea diameter or granulation of between about 1/32 of an inch and 1/2 of aninch. The final biscuit will have particles approximately in this sizerange too. Mixture of particles within this size range or particleshaving a given size within this range can be used.

Particle visual awareness and biscuit hardness maintenance are achievedby using particles containing meat and/or meat by-product which areinert with respect to the biscuit. Meat and/or meat by-productcontaining particle "inertness" herein means (a) the particle does notsmear into the biscuit dough and retains its integrity throughproduction of the final product, (b) that the color of the particlescontaining meat and/or meat by-product particle does not substantiallybleed into the biscuit dough (including any dye or colorant added tocolor dark brown the farinaceous material and/or textured vegetableprotein included in the particles), and (c) that ingredients, includingany farinaceous material and/or textured vegetable protein substitutes,within the particles containing meat and/or meat by-product do notadversely affect the hardness and microbiological stability of the finalbiscuit product.

Meat and/or meat by-product containing particle inertness is madepossible by using meat and/or meat by-product containing particleshaving: (1) a moisture content of about 35 percent by weight or lessand, (2) a water activity which is less than the water activity of thebiscuit dough during mixing of the dough, if the biscuit doughingredients were mixed without the meat or meat by-product containingparticles. The lower water activity of the meat and/or meat by-productcontaining particles substantially prevents the flow of water andprotein color from the particles to the dough during mixing of the doughingredients and the particles. Higher moisture content and a wateractivity above that of the dough would cause smearing of the softerparticles into the dough, thereby losing meat and/or meat by-productcontaining particle integrity. Also, higher moisture contents couldcreate hardness reduction by the formation of steam pockets which turninto air voids upon biscuit leavening. The discreteness of the particlesis locked in during drying of the dough.

Fresh meat and/or meat by-products can be dehydrated by known methods toachieve a moisture content of less than about 35 percent by weight.Dehydration also reduces the water activity of the meat and/or meatby-products. Generally, fresh beef has a moisture content of about 65percent by weight and a water activity of about 1.0. Dehydrating thefresh meat to a moisture content of about 40 percent results in a wateractivity of about 0.8. Dehydration to about 12 to 20 percent by weightof water results in a water activity for the meat of about 0.7 andlower. Biscuit doughs generally have a water activity of about 0.90 andabove upon completion of mixing of the non-fat solids portion, the waterand the fat portion of the dough. Preferably, meat and/or meatby-products having a moisture content of less than or equal to about 20percent by weight are used because they remain shelf stable withoutrefrigeration prior to incorporation into the biscuit.

Microbiological stability of the meat and/or meat by-product containingparticle ingredient is preferably achieved through a low water activityof 0.70 or less. This low water activity is preferably achieved bydehydration. However, the water activity can also be lowered by otherprocesses known in the art. For example, to reduce the water activity,food additives conventionally used for this purpose such as glycerin,propylene glycol, salt, corn syrup, sugar and the like can be includedin the meat and/or meat by-product containing particles in conventionalamounts.

Commercially available meats and/or meat by-products having the abovelow water activity can be used for the meat and/or meat by-productparticle ingredient of the invention. Microbioligical stability of themeat and/or meat by-products can also be achieved even at wateractivities above 0.70 by the use of antimycotics and/or antibioticsconventionally used in the art for this purpose. Exemplary of theantimycotics which can be used are potassium sorbate, sorbic acid,sodium benzoate, and the like. Suitable commercially available meatproducts and/or meat by-products which can be used are those which arestored without refrigeration and are packaged in a film of no more than5 g per sq.m per 24 hours water vapor transfer rate.

The substantial absence of color bleed by the particles containing onlymeat and/or meat by-product into the biscuit is principally due to theuse of meat products wherein the color is formed as part of the proteinmatrix. In these meat products the protein is present in its leastsoluble form, namely denatured and coagulated, and therefore the coloris also insoluble. Accordingly, bleeding of the meat protein color intothe remaining portion of the biscuit cannot take place. The subject oflack of color bleed when farinaceous material and/or textured vegetableprotein is used in place of some of the meat and/or meat by-product istreated below.

Visual awareness of the meat particles is also effected by using meatproducts having a dark brown denatured meat protein color. Productshaving a denatured meat protein color or measured by an Agtronreflectance value of 10 or less contrasts excellently with typicalbiscuit doughs to effect visual awareness.

The term "meat" is understood to apply not only to the flesh of cattle,swine, sheep, goats, horses and whales, but also to other sources ofanimal protein, such as poultry and fish. The term "meat by-product"refers to those non-rendered parts of the carcasses of slaughteredanimals, including but not restricted to mammals, poultry and fish, andincludes constituents such as liver, kidney, heart, spleen, tongue,trimmings, lungs and skins, embraced by the term "meat by-products" inthe Official Publication, "Official and Tentative Definitions of FeedIngredients," published by the Association of american Feed ControlOfficials, Inc., p. 94 (1979). The flesh of some animals, such as fishand poultry may to too light in color to provide sufficient contrastwith the biscuit dough so as to enhance visual awareness of the meatparticles. In this case, known food colorings can be added to the meatto enhance visual awareness. The meat particles and the meat by-productparticles can be used alone or in combination. Each particle may containboth meat and meat by-products from one or more animals.

The preferred particles containing only meat and/or meat by-productparticles are particles of dehydrated cured meat and meat by-products,most preferably from beef. Spiced, dehydrated cured meat and meatby-product particles are highly palatable, have an appetizing odor andare particularly preferred for use in the canine biscuits of theinvention. The preparation of dehydrated cured meat and meatby-products, spiced or unspiced, is well known in the art and does notform a part of the invention. Suitable dehydrated cured meat and meatby-products is commercially available and is commonly referred to asjerky, jerked beef or jerked meat.

Commercially available, dehydrated cured meat products which containmore than 35 percent moisture can be dried in a conventional manner towithin the above moisture content range.

Known biscuit dough formulations for the preparation of dry hard caninebiscuits can be used in the production of the biscuits of the invention.As indicated above, these doughs generally have a water activity ofabout 0.90 and above upon completion of mixing of the dough ingredients.A suitable dough contains farinaceous material, an edible oil, anantioxidant, an antimycotic, salt, animal fat, added vitamins andminerals, such as those disclosed in U.S. Pat. No. 4,229,485 at column5, lines 7 to 57. The compositions of the invention also preferablycontain at least one animal-derived proteinaceous meal such as meatmeal, bone meal and fish meal. A preferred biscuit dough for producingthe biscuits of the invention contains about 50 to about 60 percent byweight of wheat flour, about 5 to about 10 percent by weight of soybeanmeal, about 3 to about 10 percent by weight of meat and bone meal, about1 to about 5 percent by weight of wheat meal, about 1 to about 5 percentof animal fat preserved with BHA, about 20 to about 30 percent by weightof water, and about 2 to about 5 percent by weight of natural flavors,vitamin and mineral preblend, and acidulant. More generally, usefulbiscuit doughs can contain about 15 to about 35 percent by weight ofwater and about 0.5 to about 10 percent by weight of fat.

The relative amount of the meat and/or meat by-product containingparticles and the biscuit dough should be such so as to result in adried biscuit product wherein the weight percent of the particles isabout 3 to about 15 percent by weight, preferably about 5 to about 10percent by weight, of the final dried biscuit product. Compliance to NRCnutritional requirements is enhanced by even these low levels of the 40percent minimum protein meat and/or meat by-product containing particle.Lower or higher levels of the meat particles can be used providedbiscuit integrity is maintained, the meat particles do not extend abovethe surface of the biscuit so as to separate from the biscuit duringshipment, the final product remains visually attractive to the consumer,and the product is economical to produce.

In producing the dry hard canine biscuit of the invention the meatand/or meat by-product containing particles are dry-blended with thesolid non-fat portion of the biscuit dough. By incorporating the meatparticles into the solid non-fat portion of the biscuit dough, the meatparticles are distributed substantially uniformly throughout the finalbiscuit product. The portion of the particles at the surface of thebiscuit are visually apparent as discrete particles. Particlessubstantially below the surface however are also of sufficient size andintegrity to be visually apparent as discrete particle upon breaking thebiscuit in two, for example.

All mixing can be at 20 to 100 rpm. The dry-blending step is typicallyat room temperature for a period of time of about 3 minutes to about 10minutes so as to obtain a uniform mixture of the meat and/or meatby-product containing particles and non-fat portion of the biscuitdough. The dry-blended mixture is then mixed with the hot water to forma first stage dough. This methodology minimizes the occurrence of meatand/or meat by-product containing particles substantially above and onthe final biscuit surface. As a result, the opportunity for meat and/ormeat by-product containing particle loss from physical abuse duringtransit is reduced. The water which is admixed with the dry-blendedmixture is typically at a temperature of about 65° F. to about 150° F.The hot water is added, with mixing, over a period of time of about 3minutes to about 5 minutes to form the first stage dough. Then, the fatportion of the biscuit dough is admixed with the first stage dough toform the final stage dough. The fat portion is added at a temperature atwhich it is at least fluid, typically at about 100° F. to about 150° F.The fat portion is mixed for a period of time which is sufficient toform a dough whose homogeneity is visually apparent. A typical finalmixing time is about 3 minutes to about 5 minutes.

Formulation of the dough is achieved at about atmospheric pressure withmixing of the components being conveniently achieved in an upright sigmablade mixer or other bakery-type mixers. The various ingredients can beadded over a period of time or in a one-shot manner according to theabove order of addition. However, melted fat and water may be addedsimultaneously and mixed 6 to 10 minutes.

The dough is then formed into pieces by machining on a rotary molderwith specific die shapes. The dough can also be formed into pieces bysheeting followed by either a vertical or rotary cutter or by a rotarymolder. Hardness of the final biscuit is enhanced by sheeting the doughprior to cutting or molding. Suitable die and cutter shapes are thosewhich result in a round, square, triangular, T-bone or chop shapedbiscuit product and the like. The forming is accomplished atconventional temperatures of ambient to 110° F. and pressures of lessthan 75 p.s.i. (gauge), used with for example a rotary molder, avertical cutter or rotary cutter. An essential or critical feature ofthe invention is that the forming of the dough pieces is done using lowshear and/or low pressure forming means or techniques. High shear orhigh pressure forming will decimate or smear the meat and/or meatby-product containing particles or will cause bleeding or running of anydye used in the particles. The forming pressure is less than 75 p.s.i.g.

The formed pieces are then baked, followed by drying, to achieve a shelfstable product without the need of moisture barrier protection. Bakingand drying temperatures and times are those conventionally used in theproduction of a hard dry canine biscuit. The pieces are dried to obtaina biscuit having a water activity of 0.70 or less. Typical bakingtemperatures and times are about 300° F. to about an average of 475° F.for about 25 minutes to about 8 minutes. Drying conditions are typicallyabout 200° F. to about 325° F. for about 25 minutes to about 12 minutesin a forced air dryer. On a weight basis, the moisture content of thefinal biscuit product is less than or equal to about 15 percent byweight and preferably about 10 to 12 percent by weight of the finalbiscuit at 0.70 percent water activity.

While typically adding meat to a biscuit softens it, the final driedbiscuits of the invention should be sufficiently hard to stimulate thejaw bones and clean the teeth of canines. The hardness of the finalbiscuit of the invention as measured in a cracking test on a Dillondynamometer should be about 30 to about 50 lbs. for a 1/2 inch thicksample using a pinpoint tester having a 3/32 inch diameter tip. The tiphas a concave bottom with a maximum depth of 1/16 inch. In this test,the hardness reading in pounds is linearly proportional to the samplethickness. Thus, a 1/4 inch thick sample should have a hardness of about15 to 25 lbs.

The invention also broadly involves a process for preparing dry,cohesive particles, which contain meat and/or meat by-product plusfarinaceous material and/or textured vegetable protein, for inclusion inthe canine biscuit. The meat in particulate form and/or meat by-productin particulate form is admixed with the farinaceous material inparticulate form and/or the textured vegetable protein. The admixture isformed by mechanically working the mass at conditions of elevatedtemperature above about 212° F. and pressure for a time sufficient toconvert the mass into a flowable substance and extruding the flowablesubstance through a restricted orifice. The extrudate is particulatedinto particles and the particles are dried to form said dry, cohesiveparticles.

The particles can have up to 99 percent by weight, preferably from 10 to80 percent by weight, and most preferably 33 to 68 percent by weight, ofthe meat and/or meat by-product replaced by the farinaceous materialand/or textured vegetable protein. In some instances all of the meatand/or meat by-product can be replaced by the farinaceous materialand/or textured vegetable protein. The inclusion of the non-meatmaterial in the particles provides a significant cost reduction ascompared to all meat and/or meat by-product particles. Particles of meatand/or meat by-product plus farinaceous material plus textured vegetableprotein which are stable, cohesive and have particle integrity as suchor in a biscuit, are unexpected to the art.

Except as set out herein, the information herein concerning theparticles containing only meat and/or meat by-product and the stiffdough and hard biscuits containing such particles applies to theparticles containing meat and/or meat by-product plus farinaceousmaterial and/or textured vegetable protein, and the stiff dough and hardbiscuits containing such particles.

As used herein the phrase "farinaceous material" means those grainfoodstuffs containing a preponderance of starch or starch-like material.Examples of useful farinaceous grain materials are wheat, corn, oats,rye, barley, milo, rice, other cereal grains and starch from such cerealgrains. The useful forms are in particulate form, such as thefarinaceous meals or flours obtained upon grinding cereal grains such ascorn, oats, wheat, milo, barley, rice and the various millingby-products of the cereal grains, such as wheat feed flour, wheatmiddlings, wheat mixed feed, wheat shorts, wheat rod dog, oat groats,hominy feed, and any other such material. Also included are proteinconcentrates farinaceous ingredients such as wheat and corn gluten.Preferably the farinaceous material is wheat and preferably thefarinaceous material is used in flour form.

Any texturizable vegetable protein can be used. Examples of usefulvegetable proteins which can be textured are soybeans, soy proteinisolates, soy protein concentrates, cottonseed, cottonseed proteinisolates, peanuts, peanut protein isolates, sunflower seed, lentils,sesame, rapeseed, safflower seed, peanut protein concentrates, and othervegetable oil seeds and beans. The vegetable proteins are used inparticulate form such as meal and flour. Preferably the vegetableprotein is soy (preferably in flour form). The vegetable protein istexturized during treatment forming of the particle composition in thecooker extruder.

If desired, textured vegetable protein can be used in place of theuntextured vegetable protein. Particle forming in such instances can bedone using pellet mills and the like.

The farinaceous material and the textured vegetable protein can be usedseparately or in combination.

A food-pet food grade dye or colorant is preferably used to dye thefarinaceous material and/or textured (or texturizable) vegetableprotein. Preferably an artificial or synthetic food grade dye is used incombination with drug cosmetic dyes approved for use in pet foods.Examples of pet food dyes are brown and black iron oxide. The maincriterion of a useful food-pet food grade dye within the scope of theinvention is that the food-pet food grade dye has not run or bleed (atleast to any degree visible by the human eye) in the final hard biscuit.A food-pet food grade dye should be used which has a very high degree offastness for the farinaceous material and/or textured vegetable protein.The water-soluble food-pet food dyes can be used as such or can be usedemulsified in oil or fat to color the farinaceous material and/ortextured vegetable protein.

When preparing a particle containing meat and farinaceous material,preferably the particle composition contains 27 to 32 percent by weight(most preferably about 29 percent by weight) of meat, 45 to 60 percentby weight (most preferably about 51 percent by weight) of farinaceousmaterial, 10 to 20 percent by weight (most preferably about 14 percentby weight) of proteinaceous-flavoring premix, 2 to 8 percent by weight(most preferably about 5.5 percent by weight) of seasoning and 0.1 to 2percent by weight (most preferably about 0.5 percent by weight) ofcolorant. The proteinaceous-flavoring premix preferably contains 40 to65 percent by weight (most preferably about 54 percent by weight) ofprotein, usually soy, and 35 to 60 percent by weight (most preferablyabout 46 percent by weight) of flavorant(s). The particle compositioncan optionally contain up to about 10 percent by weight, generally 5 to10 percent by weight, of fat.

When preparing a particle containing meat and vegetable protein,preferably the particle composition contains 27 to 32 percent by weight(most preferably about 29 percent by weight) of meat, 60 to 70 percentby weight (most preferably about 65 percent by weight) of vegetableprotein, 2 to 8 percent by weight (most preferably about 5.5 percent byweight) of seasoning and 0.1 to 2 percent by weight (most preferablyabout 0.5 percent by weight) of colorant. The particle composition canoptionally contain up to about 10 percent by weight, generally 5 to 10percent by weight, of fat.

Preferably the particulated meat is prepared by particulating frozenmeat, and preferably the particulating is achieved by chopping and thengrinding the frozen meat.

In one embodiment all of the ingredients are thoroughly admixed forexample in a blender. Preferably the ingredients are preconditionedduring mixing in a blender which has a jacketed heat or a steaminjector. The mixture is fed into a hopper of a cooker extruder.

In another embodiment the meat, about half of the seasoning and theoptional fat are thoroughly admixed for example in a blender. Preferablysuch first mixture is preconditioned during mixing in a blender whichhas a jacketed heater or a steam injector. The other half of theseasoning and the remainder of the ingredients are mixed to form asecond mixture. The first and second mixtures are separately andsimultaneously fed into a hopper of a cooker extruder. The two mixturesare mixed by the action of the extruder. Instead of using the secondmixture as such, the ingredients of the second mixture can be separatelyfed into the hopper.

The blended mixture is then extrusion cooked at conditions of elevatedtemperature and pressure at about 212° F. to about 400° F. and about 15p.s.i.g. to about 300 p.s.i.g. respectively. The process of thisinvention may be practiced in a conventional cooker extrusion device.The rotating screw of the extruder device creates a high pressure on thematerial mixed in the extruder. It is believed that the particularmaterial changes form until it finally flows in a generally fluentmanner, even squeezing around the outer periphery of the screw in arecirculating fashion column to cause a severe mechanical working of thesubstance. The pressures in the extruder are elevated to about 100p.s.i.g. and typically will fall within the range of 100 to 200 p.s.i.g.All of the pressure and the high temperatures result from the frictionbetween the flowing products and components of the extruder. During theextrusion operation, cooling water is passed through the rear endforward jacket for temperature control. The mixture is converted to aflowable substance which emerges from the nozzle of the extruder.

The unexpanded extrudate has a bulk density of about 30 lbs. per cubicfoot. (A fully expanded extrudate would have a bulk density of about 5lbs. per cubic foot.) When the particle composition contains vegetableprotein as replacement for part or all of the meat and/or meatby-product, preferably the extrudate is partially expanded, having abulk density of about 15 to about 20 lbs. per cubic foot. Partialexpansion is achieved by conventional extruding techniques.

The extruded material is cut into pieces or particles of having adiameter or granulation of between about 1/8 inch and about 1/2 inch,preferably 3/16 inch. The final hard biscuit will have particlesapproximately in this size range too. Mixtures of particles within thissize range or particles having a given size within this range can beused. The extruded material can be particulated by any suitable means,but preferably staggered cutting blades are used which are located veryclose to the extruder die.

The extruded particles can be dried or can be dehydrated by knownmethods to achieve a moisture content of less than about 35 percent byweight. Dehydration also reduces the water activity of the meat and/ormeat by-products. Preferably the particles are dehydrated to about 12 to20 percent by weight water which results in a water activity for themeat of about 0.7 and lower.

The dried particles can be weighed and bagged for storage until usage.The dried particles are shelf stable without refrigeration prior toincorporation into the hard biscuit. The dehydrated particles, spiced orunspiced are highly palatable, have an appetizing odor and areparticularly preferred for use in the hard canine biscuits of theinvention. The dried particles do not smear into the hard biscuit doughand retain its integrity through production of the final product. Theparticle color does not substantially bleed into the hard biscuit dough.

The invention is further illustrated in the following examples whereinall percentages, parts, ratios and proportions are by weight and alltemperatures are in degrees Fahrenheit unless otherwise indicated:

EXAMPLE 1

In this example, spiced dehydrated cured beef granules having a moisturecontent less than 35 percent by weight, a granulation between 1/32 of aninch and 1/2 inch, and having a dark brown denatured meat protein colorof Agtron reflectance value of 10 or less were used. The spiceddehydrated cured meat granules were obtained by granulating dehydratedcured meat having the composition:

    ______________________________________                                        Dehydrated Cured Meat                                                                              Pounds                                                   ______________________________________                                        Meat By-Products     650                                                      Meat                 268                                                      Natural Flavors      1                                                        Spices               29                                                       Cure (Sodium Nitrite)                                                                              1                                                        Potassium Sorbate    0.5                                                                           949.5   pounds                                           ______________________________________                                    

Then, 75 pounds of the spiced dehydrated cured meat granules werecombined with the non-fat solids portion of a biscuit dough, the fatportion of the biscuit dough and water to form a dough in accordancewith the process of the invention. The ingredients, relative amounts,and the process for making the biscuits were:

    ______________________________________                                        Biscuit and Meat Chips Pounds                                                 ______________________________________                                        Wheat Flour            940                                                    Soybean Meal           135                                                    Dehydrated Cured Meat  103                                                    Meat and Bone Meal     100                                                    Wheat Meal             40                                                     Animal Fat preserved with BHA                                                                        32                                                     Natural Flavors        17                                                     Vitamin and Mineral Preblend                                                                         25                                                     Acidulant              4                                                      Water                  490                                                                           1886    pounds                                         ______________________________________                                    

The dehydrated cured meat was dry-blended with the solid non-fat portionof the biscuit dough in an upright sigma blade mixer at 20 rpm for 10minutes. Then, the 490 pounds of water at a temperature of 150° F. wasadded together with 140° F. fat to the preblend and mixed for 6 minutesto form the dough. The dough was then machined on a rotary molder havingdies engraved to a depth of 0.415 inch for the formation ofapproximately 7/16 inch thick round, T-bone and chop shapes. The formedpieces were then baked in a band oven for 9 minutes followed by dryingat 250° F. for 20 minutes in a band dryer to achieve dry, hard shelfstable canine biscuits of about 1/4 with thickness. The bakingtemperatures in the band oven were:

    ______________________________________                                        Band Oven Baking Temperatures                                                                       Zone                                                    ______________________________________                                         .sup. 530° F. 1                                                       530                   2                                                       550                   3                                                       540                   4                                                       400                   5                                                       520                   6                                                       Off                   7                                                       Off                   8                                                       Off                   9                                                       ______________________________________                                    

The product was dump-packed into a carton without the need for moisturebarrier protection.

Hardness tests on the product using a Dillon dynamometer as describedabove resulted in hardness readings in the range of 30 to 50 lbs.

The product and biscuits prepared in the same manner except for theinclusion of the meat granules were fed to dogs in 35 tests. The numberof dogs in each test ranged from 11 to 32. The feedings were for 3consecutive days in a split plate for testing preference. The biscuitswere fed as a treat 4 to 5 hours after each dog's main meal. The mainmean supplied 100 percent of each dog's calorie demand. The biscuitcontaining the meat granules was preferred up to 8:1 indicating astatistically significant preference level.

EXAMPLE 2

In this example, special dehydrated meat granules containing farinaceousmaterial was prepared. The formulation had the following composition:

    ______________________________________                                        Ingredients            Percent                                                ______________________________________                                        Meat                   29                                                     Farinaceous material   51                                                     Proteinaceous/flavoring premix                                                                       14                                                     Seasoning              5.5                                                    Coloring               0.5                                                                           100    percent                                         ______________________________________                                    

The proteinaceous/flavoring premix contained 54 percent protein (soy)and 46 percent flavoring. The composition further contained 7 percent offat.

The meat was prepared from frozen meat (beef) which was chopped andground. The farinaceous material was in flour form; theproteinaceous/flavoring agent was also in fine particle form. The colorwas synthetic brown food grade and brown pet food grade iron oxide dyesthat had good fastness for the non-meat ingredients. All of theingredients were thoroughly mixed (blended together) using a blender.Steam was injected into the mixture as it was blended to preconditionit. The mixture was fed into the hopper of a cooker extruder.

The cooker extruder was a conventional cooker extruder having steam andwater jackets. Cooling water at room temperature was passed through thecooling jackets. The screw in the extruder was rotated at about 450 rpm.The extruder cooked and formed the material, which was continuouslypassed through it. The protein in the material texturized by the heat,pressure, shear, etc. The material was continuously passed through theextruder die and then the extrudate cut into 3/16 inch pieces usingstaggered cutting blades. The extrudate was not expanded and had a bulkdensity of about 30 lbs/ft.³. 95 percent of the particles passed througha -4 U.S. mesh screen and stayed on a +14 U.S. mesh screen. The other 5percent was fines. The collected particles were dried to a moisturecontent of 14 percent by weight. The dried particles were cohesive,appetizing in appearance and color and stable when handled. The driedparticles were weighed and bagged.

Some of the dried particles were then put into a dough like the one inExample 1 using the procedure of Example 1. The dough and particles werethen formed as in Example 1 into various shapes, and bakes and dried asin Example 1 to form dry, hard, shelf stable, 1/4-inch thick, caninebiscuits. The particles in the dried final biscuit were visablydiscrete, had not smeared and did not show any color bleed.

EXAMPLE 3

In this example, spiced dehydrated cured meat granules containingtextured soy protein was prepared. The formula had the followingcomposition:

    ______________________________________                                        Ingredients           Percent                                                 ______________________________________                                        Meat                  29                                                      Vegetable protein (soy)                                                                             65                                                      Seasoning             5.5                                                     Color                 0.5                                                                           100    percent                                          ______________________________________                                    

The composition further contained 7 percent fat.

The meat was prepared from frozen meat (beef) which was chopped andground. The farinaceous material was in flour form; theproteinaceous/flavoring agent was also in fine particle form. The colorwas synthetic brown food and pet food grade dyes that had good fastnessfor the non-meat ingredients.

The meat, half of the seasoning and the optional fat were thoroughlymixed in a blender having a hot water jacket, to form a first mixture.The other half of the seasoning and the rest of the ingredients weremixed, to form a second mixture. The first and second mixtures wereseparately and simultaneously fed into the hopper of a cooler extruder.

The cooker extruder was a conventional cooker extruder having steam andwater jackets. Cooling water at room temperature was passed through thecooling jackets. The screw in the extruder was rotated at about 400 rpm.The extruder cooked and formed the material, which was continuouslypassed through it. The vegetable protein in the mixture was texturizedby the heat, pressure, shear, etc. The material was continuously passedthrough the extruder die and the extrudate cut into 3/16 inch piecesusing staggered cutting blades. The extrudate was partially expanded(using a proper size die to achieve such upon exit to atmosphericpressure) and had a bulk density of about 20 lbs/ft³. The collectedparticles were dried to a moisture content of 14 percent by weight. Thedried particles were cohesive, appetizing in appearance and color andstable when handled. The dried particles were weighed and bagged.

Some of the dried particles were then put into a dough like the one inExample 1 using the procedure of Example 1. The dough and particles werethen formed as in Example 1 into various shaped, and baked and dried asin Example 1 to form dry, hard, shelf stable, 1/4-inch thick, caninebiscuits. The particles in the dried final biscuit were visablydiscrete, had not smeared and did not show any color bleed.

What is claimed is:
 1. A method for making dry hard canine biscuits froma final biscuit dough comprising:(a) dry blending particles, whichcontain (i) meat and/or meat by-product and (ii) farinaceous materialand/or textured vegetable protein, and which have a moisture content ofless than or equal to about 35 percent by weight of said particles, withnon-fat solids to form a substantially homogeneous dry blended mixture,no fat being added in step (a) except for the indigenous fat which ispresent in said particles, said particles being present in an amount ofabout 3 to about 25 weight percent, based on the total weight of saiddry hard canine biscuits and said particles having a water activitywhich is less than the water activity of said final biscuit dough; (b)admixing water with said dry blended mixture (a) to form a first stagedough, said water being present in an amount of about 15 to about 35weight percent, based on the total weight of the final biscuit dough;(c) mixing an amount of added-fat with said first stage dough to formsaid final biscuit dough, said added-fat being present in an amount ofabout 0.5 to about 10 weight percent, based on the total weight of saidfinal biscuit dough; (d) forming said final biscuit dough into piecesusing a low shear forming pressure of less than 75 p.s.i.g.; and (e)baking and drying said pieces to form said dry hard biscuits, which areshelf stable and have said particles present as discretevisually-apparent particles distributed substantially uniformlythroughout and embedded in the surface of said dry hard canine biscuits.2. Method as claimed in claim 1 wherein said particles contain up to 90percent by weight of said farinaceous material and/or textured vegetableprotein.
 3. Method as claimed in claim 1 wherein said farinaceousmaterial is wheat flour or wheat meal.
 4. Method as claimed in claim 1wherein said textured vegetable protein is textured soy protein. 5.Method as claimed in claim 1 wherein said particles contain up to 70percent by weight of said farinaceous material.
 6. Method as claimed inclaim 1 wherein said particles contain up to 70 percent by weight ofsaid textured vegetable protein.
 7. Method as claimed in claim 1 whereinsaid water and said fat portion in steps (b) and (c) are addedsimultaneously to the dry blended mixture of step (a).
 8. Method asclaimed in claim 1 wherein the particles of step (a) are shelf stableparticles.
 9. Method as claimed in claim 1 wherein the particles of step(a) have a moisture content of less than or equal to about 20 percent byweight of the particles.
 10. Method as claimed in claim 1 wherein saidpieces of step are dried a moisture content of 10 to 12 percent byweight.
 11. Method as claimed in claim 1 wherein said biscuits have ahardness equivalent to a reading of 30 to 50 lbs. for a biscuit having athickness of about 1/2 inch measured on a Dillon dynamometer having apinpoint tester with a 3/32 inch diameter tip having a concave bottom.12. Method as claimed in claim 1 wherein said particles have agranulation of between about 1/32 inch and about 1/2 inch.
 13. Method asclaimed in claim 1 wherein said particles have a dark brown denaturedmeat protein color of Agtron reflectance value of 10 or less.
 14. Methodas claimed in claim 1 wherein the particles of step (a) have a wateractivity of 0.70 or less.
 15. Method as claimed in claim 1 wherein thewater which is admixed with the dry blended mixture is at a temperatureof about 65° F. to about 150° F.
 16. Method as claimed in claim 15wherein the fat portion of the biscuit dough is added at a temperatureof about 100° F. to about 150° F.
 17. Method as claimed in claim 16wherein said dry blending is for a period of time of about 3 minutes toabout 10 minutes, the dry blended mixture is mixed with water for aperiod of time of about 3 minutes to about 5 minutes, and wherein saidmixing of the fat portion is for a period of time of about 3 minutes toabout 5 minutes.
 18. Method as claimed in claim 1 wherein said formingof said final dough into pieces is by rotary molding.
 19. Method asclaimed in claim 1 wherein said pieces are formed by sheeting said finaldough followed by molding in a rotary molder.
 20. Method as claimed inclaim 1 wherein said pieces are formed by sheeting said final doughfollowed by cutting with a vertical cutter or a rotary cutter. 21.Method as claimed in claim 1 wherein said pieces are dried to obtain abiscuit having a water activity of 0.70 or less.
 22. A method forincorporating food particles into a final biscuit dough to obtain harddry canine biscuits, comprising:(a) dry blending said particles, whichcontain (i) meat and/or meat by-product and (ii) farinaceous materialand/or textured vegetable protein, having a moisture content of lessthan or equal to about 35 percent by weight of said particles, withnon-fat solids, said particles having a water activity which is lessthan the water activity of said final biscuit dough, and said particlesbeing present in an amount of about 3 to about 25 weight percent, basedon the total weight of said dry hard canine biscuits; (b) admixing waterwith said dry blended mixture to form a first stage dough, saidadded-water being present in an amount of about 15 to about 35 weightpercent, based on the total weight of said final biscuit dough; (c)mixing with said first stage dough to form a final dough, said fat beingpresent in an amount of about 0.5 to about 10 weight percent, based onthe total weight of said final biscuit dough; (d) forming said finaldough into pieces using a low shear forming pressure to produce dry hardbiscuits, wherein the water activity of said dry hard biscuit is 0.70 orless, said biscuit having said particles present as discretevisually-apparent particles distributed substantially uniformlythroughout and embedded in the surface of said dry hard canine biscuits.23. Method as claimed in claim 22 wherein said particles contain up to90 percent by weight of said farinaceous material and/or texturedvegetable protein.
 24. Method as claimed in claim 23 wherein saidfarinaceous material is wheat flour or wheat meal.
 25. Method as claimedin claim 23 wherein said textured vegetable protein is textured soyprotein.
 26. Method as claimed in claim 22 wherein said particlescontain up to 70 percent by weight of said farinaceous material. 27.Method as claimed in claim 22 wherein said particles contain up to 70percent by weight of said textured vegetable protein.
 28. Method asclaimed in claim 22 wherein the water activity of said dough withoutsaid particles is at least 0.90.
 29. Method as claimed in claim 22wherein said particles of step (a) are shelf stable.
 30. Method asclaimed in claim 22 wherein said water and said fat portion in steps (b)and (c) are added simultaneously to the dry blended mixture of step (a).